Experimental study of wideband in-band full-duplex communication based on optical self-interference cancellation

In this paper, we experimentally demonstrate and study a wideband in-band full-duplex (IBFD) wireless communication system based on optical self-interference cancellation (SIC). The optical SIC performances based on antennas for broadband IBFD are firstly evaluated within high frequency bands (> 10GHz). In this system, two electro-absorption-modulated lasers (EMLs) and a balanced photo-detector (BPD) are employed to remove the wideband self-interference within received wireless signal. By theoretical derivation and experimental verification, the impact factors of SIC are analyzed, especially for non-flatness wireless channel case. Experimental results show more than 30-dB cancellation depth in 100-MHz bandwidth with employment of horn antennas. Besides, IBFD transmission performance based on OFDM signals for different bandwidth with 11.15-GHz center frequency is also demonstrated, and ~52.2- dB•Hz^2/3 spurious-free dynamic range (SFDR) is obtained.